1. Technical Field
The present invention relates to a spindle motor.
2. Description of the Related Art
A spindle motor is commonly used as an apparatus for rotating a mounted disk, and may be used in various devices such as optical disk drives, magnetic disk drives, and hard disk drives.
When a spindle motor undergoes rotation, however, various factors, such as defects in the spindle motor parts, eccentricity in the assembly of the disk, and irregular airflow within the disk drive, may lead to the occurrence of vibration.
Such vibration is liable to cause track misregistration (TMR), and hence to an increase in position error signals (PES), resulting in lower reliability in reading and writing data. Problems caused by vibration have become increasingly serious due to the rapid increase of data density in the disk.
In particular, if a base plate is rigidly coupled to the rotor, the vibration may be transferred to the encoder, etc., that reads signals from the disk, leading to even more serious problems.